2003 PLC doesn't start due to failure of power supply

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1

Hello colleagues.

I have two B&R PLCs installed on two presses, but the following problem occurs randomly from time to time.

I turn on the panel, but the B&R 2003 PLC does not turn on. After turning on the panel, I measured the voltage at the CPU input (power supply: +24 VDC) and it was 24 V, without variations, but the PLC still does not turn on.

The PLC only turns on after blow hot air on the area highlighted in the image (one or two minutes later).

I noticed that this event occurs mainly on cold days.

Has this situation ever happened to any of you?

I believe it is an internal problem in the CPU power supply, which prevents it from starting, involving some thermal component (such as PTC or NTC, where the component reacts to the increase/decrease in temperature). However, I did not want to disassemble the power supply because I saw that it is integrated directly into the CPU (model 7CP476-60.1).

Any help is welcome.

Thanks.

Image - Blowing hot air in power supply region
Image - Blowing hot air in power supply region561×604 35.8 KB

2

Hello,

It’s best if you replace the CPU. Since the controller is discontinued, I suggest replacing it with a currently available CPU. Your controller has a Motorola processor (SG3). Since B&R only uses Intel processors (SG4), you’ll need to adapt your software accordingly.

Regards
Stephan

3

I would agree with Stephan that there is a defect.

It sounds like an aged electrolytic capacitor in the switching power supply. If you heat them up, you get a little more capacity back for a short time.

You can try sending the control unit to B&R Austria for repair.